Field of the Invention
The present invention relates to wireless communication, and more particularly, to a traffic steering method in a wireless communication system and a device supporting the same.
Related Art
3rd Generation Partnership Project (3GPP) long term evolution (LTE) which is enhancement of Universal Mobile Telecommunications System (UMTS) is introduced as 3GPP release 8. The 3GPP LTE uses orthogonal frequency division multiple access (OFDMA) in a downlink and uses Single Carrier-frequency division multiple access (SC-FDMA) in an uplink. Multiple input multiple output (MIMO) having a maximum of 4 antennas is adopted. In recent years, 3GPP LTE-Advanced (A) which is evolution of the 3GPP LTE has been discussed.
A wireless communication system can support providing a service through a plurality of access networks to a terminal. For example, the terminal can receive the service from a 3GPP access network which is a mobile wireless communication system and further, receive the service from non-3GPP access networks such as Worldwide Interoperability for Microwave Access (WiMAX), Wireless Local Area Network (WLAN), and the like.
The terminal can generally receive the service by establishing a connection with the 3GPP access network. Meanwhile, when traffic overload occurs in the 3GPP access network, processing traffic which the terminal intends to process through another access network, that is, the non-3GPP access network can improve overall efficiency of the network. Variably processing the traffic through the 3GPP access network and/or the non-3GPP access network is referred to as traffic steering.
A policy for interlocking the 3GPP access network and the non-3GPP access network such as Access Network Discovery and Selection Functions (ANDSF) can be configured in the terminal for the traffic steering and the policy is managed separately from an interlocking policy configured by the network.
Meanwhile, during the traffic steering, a specific access network can command or instruct the terminal to move the traffic to another access network. In this case, the specific access network may not accurately know the traffic of the terminal. When the terminal moves all traffic to be processed by the specific access network to another access network according to the command or instruction, the terminal can be separated from the specific access network. Then, there is a problem in that the service which needs to be provided by the specific access network may be interrupted/stopped.